JPH05238614A - Heating device - Google Patents

Abstract

PURPOSE:To always stabilize film draw controlling and film transporting by constituting a film draw controlling means in such a way that film draw moving speed in the film cross direction is controlled according to the detection signal from an endless film cross directional drawing position detecting means. CONSTITUTION:Taking the direction crossing the transferring direction of an endless film 11 as film cross direction, a film draw motion controlling means, which makes film draw motion, arrow marks B and C, become endless reciprocating motion in a specified range in the process to transfer the film 11, is provided. This film draw motion controlling means comprises the deep end side shaft 20 of a driven roller 12, a swing lever 6, a stepping motor 23 and a micro computer 26. The film draw motion controlling means has a plurality of film draw position detecting sensors 16 to detect the draw of the endless film 11 in the cross direction and varies the inclination quantity of the driven roller by controlling the number of drive pulses given to the stepping motor 23 according to this detected signal to variably vary the draw speed of the endless film 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an endless belt-shaped (loop-shaped) heat-resistant film which is rotatably conveyed, and a heating element arranged inside the endless film. The present invention relates to a film heating type heating device in which the material to be heated is brought into close contact with the side and is conveyed and passed through the position of the heating body together with the film, so that the heat of the heating body is applied to the material to be heated through the film.

[0002]

2. Description of the Related Art A film heating type heating device as described above is known from Japanese Patent Application Laid-Open No. 63-313182, and an image heating and fixing device in an image forming apparatus such as an electrophotographic copying machine, a printer or a fax machine, That is, electrophotography, electrostatic recording,
Direct or indirect (transfer) to the surface of the recording material (electrofax sheet, electrostatic recording sheet, transfer material sheet, printing paper, etc.) using toner made of heat-meltable resin by image forming process means such as magnetic recording. It can be utilized as an image heating and fixing device that heats and fixes, as a fixed image, an unfixed visible image (toner image) corresponding to the target image information formed by the method (3) on the recording material carrying the image.

Further, it can be used, for example, as an apparatus for heating a recording material carrying an image to modify the surface properties of gloss and the like, an apparatus for post-treatment, etc.

Regarding the film heating type fixing device, in comparison with other heat fixing type devices such as a heat roller type, a hot plate type, a flash fixing type and an oven fixing type,
Since a low heat capacity linear heating body can be used as the heating body and a thin heat-resistant film having a thickness of, for example, about 40 μm can be used as the film, it is possible to shorten the rise time to a predetermined fixing temperature and save power. Since the separation point between the film and the recording material can be set separately, toner offset can be prevented, and various other drawbacks of the other type apparatus can be solved, which is effective.

The film may be of an endless type so as to be rotated and conveyed to be repeatedly used, or it may be an apparatus structure to make an endless roll-wound film unwound and run.

In a film heating type heating device using an endless type film, the film is rotated in the width direction (the direction orthogonal to the film rotational transfer direction, the rotational axis direction of the film) during the rotational transfer process of the film. Since the film moves along the longitudinal direction of the film conveying path member such as the suspension conveying roller, a measure for restricting the deviation is taken.

As the displacement control means, for example, a film is a thin film and a material having a low elasticity is used such as polyimide by restricting it with a rib or a flange member or forming the film suspending and conveying roller into a crown shape. In some cases, it is difficult to regulate the shift of the film, and it is difficult to secure stable rotational transportability of the film.

Therefore, a means for detecting the shift position of the film in the width direction is provided, and when it is detected that the shift of the film in one side in the width direction reaches a predetermined limit position, the shift of the film is determined. Actuating the means for displacing the film transport path member so as to change it to the other side which is the return direction, and conversely, when it is detected that the shift movement of the film to the other side in the width direction has reached the predetermined limit position, An endless film is provided by providing a film deviation movement control mechanism (film deviation direction changing means) configured to operate means for displacing the film transport path member so as to change the deviation movement of the film to one side which is the return direction thereof. There is used a means / structure for making the lateral movement of the film in the widthwise transporting process of the film infinitely reciprocating within a predetermined fixed range (Japanese Patent Application No. 63-159721).

[0009]

However, a film heating type heating device using an endless film provided with the above-mentioned film shift movement control mechanism (hereinafter, described as a fixing device of an image forming apparatus) is also provided. There is instability in the film deviation control as described below.

That is, the film shift control mechanism switches the shift direction of the film between the forward and reverse directions under a certain fixed condition. However, since the thin film is conveyed, the shift force is strong. Frequently performing reciprocating motion of the film (changing the direction of deviation) to control the deviation movement increases damage to the film such as film wrinkles, so weaken the deviation force and control the deviation movement. I have to.

However, in the initial state, the film reciprocation control for the film shift movement control can be guaranteed by a certain degree of part precision or initial adjustment, but when some external condition is added, the film transport path member is displaced. The film does not move in the specified direction, that is, it runs backwards,
On the contrary, there may be a case of moving at a sudden speed,
Stable film running cannot be realized due to skewing of the recording material as the heated object and film wrinkling.

As the above-mentioned external conditions, the influence of heat is the most important, and it is not necessary to consider an extreme temperature difference in general film (belt) conveyance, but in the present invention, the target device is a heating device. Therefore, in the temperature rising state, 150 ° C to 200 ° C
The temperature of each component rises to a certain degree. Due to this temperature rise, the coefficient of friction of the film transport path member and the surface of the heating body naturally changes (generally decreases), so that the initial reciprocating condition of the film deviation control may be destroyed.

In addition, there is a temperature distribution in the heating element itself, the size of the recording material to be passed, and the temperature rise in the non-sheet passing area based on the one-sided reference. When the film is heated, the film conveying path member also has a temperature gradient, and a difference in thermal expansion occurs in the longitudinal direction, resulting in a change in the film due to a difference in the conveying speed.

Further, due to abrasion, the friction coefficient changes due to abrasion of the inner surface of the film, the film transporting means, and the surface of the heating body, which also causes the condition of the film deviation to be changed.

Further, in the film heating type heating device, since the film is conveyed while rubbing the fixedly supported low heat capacity heating element, the fluorine-based heat-resistant grease is used for the purpose of preventing vibration at the rubbing portion and reducing torque. May be applied to the inner surface of the film for lubrication. In this case, since the grease viscosity has temperature dependency and the grease application state after the initial and after the durability change, this also changes the film deviation condition, which affects the above-mentioned film deviation control. Will be given.

That is, the conventional film shift movement control mechanism alternately repeats the film shift direction switching operation in two directions of the film width direction with respect to the film shift, and as a result, the film shift is allowed within a certain range. Since the control value is limited to 2, the control value has only two values, and the control value must be determined so that the film always moves in the specified film width direction.

However, since the moving force (deviation force) of the film largely changes depending on the temperature of the film and the film conveying path member and the change of the surface condition due to the durability, it is necessary to decide the control value with a margin with respect to this change. Therefore, the amount of film deviation control movement in the steady state is inevitably large and stress on the film becomes a problem, and since the film deviation movement speed is fast, it is necessary to frequently perform film reciprocation control for deviation movement control. Therefore, it has been difficult to accurately store the film deviation in a narrow range.

The present invention is intended to solve the above problems. That is, it is an object of the present invention to provide a film heating type heating device which is provided with means for adjusting a change in the film shift speed due to a temperature factor and a change in durability, and which enables stable film shift control and film transport at all times.

[0019]

The present invention is a heating device characterized by the following constitutions.

(1) It has an endless film and a heating body arranged on the inner surface side of the endless film, and a heated body is brought into close contact with the outer surface side of the endless film so that the heating body position is conveyed along with the film. It is a heating device of a film heating system that gives the heat of the heating body to the heated body through the film by making the direction orthogonal to the transport direction of the endless film the film width direction, in the transport process of the endless film. A film deviation control means for making the lateral movement movement of the film in the width direction endless reciprocating motion within a predetermined range, the film deviation control means detecting a plurality of deviation positions in the width direction of the endless film. And a means for controlling the lateral movement speed of the endless film in the width direction according to the detection signal of the detection means. Heating and wherein the.

(2) A means for displacing the conveying path member of the endless film to switch the direction of the lateral movement movement of the endless film in the width direction, and by changing the displacement amount of the conveying path member of the endless film, the endless film The heating device according to (1), further comprising a unit for controlling a lateral movement speed of the film in the width direction.

(3) It has an endless film and a heating element arranged on the inner surface side of the endless film, and a heating object is brought into close contact with the outer surface side of the endless film so that it passes through the heating element position together with the film. It is a heating device of a film heating system that gives the heat of the heating body to the heated body through the film by making the direction orthogonal to the transport direction of the endless film the film width direction, in the transport process of the endless film. Position detecting means for detecting the film deviation position, film deviation force varying means capable of changing the deviation force in the width direction of the endless film in multiple stages, and the endless film with respect to a predetermined reference position. When it is detected by the position detecting means that the moving body is moving in the separating direction, a deviation force in the reference position direction is predetermined. The endless film deviation control means configured to decrease the moving speed of the endless film in the detaching direction by controlling the deviation force varying means so as to increase in a stepwise manner. Heating device.

[0023]

In other words, as described in (1) and (2) above, the lateral movement position of the endless film is detected at a plurality of positions, and the closer the endless film is to the position farther from the center, the more the deviation force is. By making it stronger, it is a stable film that does not apply an undesired offset force to the film from the initial state, and does not cause extreme damage to the film even if the film shift speed changes due to durability or thermal changes. It is possible to control the deviation.

Further, as in (3), the control value for the film shift movement is set in multiple stages, and control is performed to minimize the film shift movement speed rather than simple position control, that is, the return movement speed of the shifted film is gradually increased. By reducing the temperature to a stop and controlling it to rotate slowly and repeatedly in the vicinity of the center, the stress on the film is reduced while sufficiently responding to changes in temperature and surface conditions, and the durability of the film is improved. It has become possible to improve.

Further, since the film shift speed is slowed down, the positional accuracy can be improved with easy control.

[0026]

【Example】

<First Embodiment> (FIGS. 1 to 12) (A) Configuration of an example of an image forming apparatus (FIG. 4) FIG. 4 is a schematic view of an example of an image forming apparatus incorporating an image heating and fixing device 1 as a heating device according to the present invention. It is a block diagram. The image forming apparatus of this embodiment is a reciprocating platen type / rotary drum type / transfer type electrophotographic copying machine, and the construction and image forming process of this copying machine are well known, so only a brief description will be given.

Reference numeral 152 denotes an upper surface plate 151 of the copier machine housing 150.
It is a reciprocating-type original platen glass disposed above, and is reciprocally driven in the left-right direction by a driving mechanism (not shown). The original 153 is placed at a predetermined position on the upper surface of the original platen glass 152 with the image surface to be copied facing downward, and the original is pressed and set by the original press plate 154.

The downward image surface of the set original 153 is subjected to slit illumination scanning by sequentially passing through the illumination unit 155 during the forward or backward movement of the original table glass 152.
Reference numeral 156 represents an illumination light source.

Then, the downward document surface reflected light of the slit illumination light is sequentially image-formed by the image forming lens (short focus image forming element array) 157 on the surface of the photosensitive drum 158 which rotates in synchronization with the scanning of the document image.

The photosensitive drum 158 is subjected to uniform positive or negative charging processing by the discharger 159, and then subjected to the above-mentioned image forming exposure, whereby electrostatic latent images corresponding to the original image are sequentially formed on the drum peripheral surface. Is formed.

Next, the photosensitive drum 15 on which the latent image is formed
The eight surfaces sequentially pass the position of the developing device 160 and undergo sequential development of latent images. The developed image on the surface of the photosensitive drum 158 reaches the position of the transfer discharger 161 by the subsequent rotation of the photosensitive drum.

On the other hand, the transfer material P as a recording material is transferred from the transfer material cassette 162 into the copying machine by the paper feed roller 163.
The leading end portion is received by the nip portion of the registration roller pair 164 which is fed to the sheet and is in a rotation stopped state at that time. Then, the rotational driving of the registration roller pair 164 is started at a predetermined timing synchronized with the rotation of the photosensitive drum 158, whereby the transfer material P is guided by the guide member and is fed toward the photosensitive drum 158, The developed image on the surface of the photosensitive drum 158 is sequentially transferred to the transfer material P by being introduced into the transfer portion between the transfer unit 158 and the transfer discharger 161.

The copying material P that has received the image transfer is the photosensitive drum 15.
The paper is sequentially separated from the eight surfaces by separation means (not shown), introduced into a fixing device 1 described later by a conveying device 165 and subjected to image fixing, and a discharge roller 166 as an image formed product (copy) is discharged to the outside by a discharge tray 167. Is discharged to. The surface of the photosensitive drum 158 after the image transfer is cleaned by the cleaning device 168 and repeatedly used for image formation.

(B) Fixing device 1 (FIGS. 1 to 3) FIG. 1 is an external perspective view of the image heating and fixing device 1 as the heating device used above, FIG.
Is a side view.

Numerals 13 and 12 are a pair of left and right endless film driving rollers which are arranged substantially parallel to each other, and a driven roller which also serves as a tension roller.
A heating element disposed substantially parallel to the rollers below the position between 3 and 12, 11 is both the rollers 13 and 12 and the heating element 14.
The endless film is stretched between the three members, and the drive roller 13 is rotationally driven in the clockwise direction indicated by the arrow by a drive system (not shown) including the drive motor 27.
Is rotated and driven in a clockwise direction at a predetermined peripheral speed.

The film 11 is a heat resistant film having a total thickness of 100 μ, more preferably less than 40 μ. In this embodiment, an endless film having a thickness of about 20 μm such as polyimide, polyetherimide, PES, PFA or the like as a base film and a release layer such as PTFE coated on the image contact surface by about 10 μm is used.

The heating element 14 is the endless film 1 described above.
1 is fixedly arranged (fixedly supported by the fixing device) on the inner surface side of the descending side film portion 1. This heating element 14 is a film 1
It is a low-heat-capacity linear heating element (hereinafter referred to as a heater) having a length in the direction crossing the plane movement direction of 1, that is, the film width direction, and generates heat when energized.

Numeral 15 is a pressure roller having a rubber elastic layer having a good releasing property such as silicone rubber.
The film portion on the descending side of the endless film 11 is sandwiched between and by an unillustrated urging means, for example, a total pressure of 4 to 5
The film is brought into pressure contact with a contact pressure of kg, and as the film moves, it rotates in the forward direction in the film moving direction at a peripheral speed substantially the same as the film speed.

A transfer device 165 from the transfer portion 161 (FIG. 4).
The transfer material P having the unfixed toner image t (heat-melting toner) carried to the fixing device 1 on the upper surface is guided to the entrance guide 10 and heated by the heater 14 with the endless film 11 interposed therebetween. The film 11 at the pressure contact portion (fixing nip portion) N formed by the pressure roller 15 and the pressure roller 1
5 and the unfixed image surface comes into close contact with the surface of the film 11 in the state of surface movement in the same direction at substantially the same speed as the conveyance speed of the transfer material P and the fixing nip N in the overlapping state with the film 11. Pass through while receiving the clamping pressure. In this process, the toner image bearing surface of the transfer material P is heated by the heat of the heater 14 through the film 11, and at least the surface layer portion of the toner image t is completely softened and melted and heat-fixed to the surface of the transfer material P. .. When the transfer material P that has passed through the fixing nip portion N then passes through the position of the film driving roller 13, the roller 1
The curvature of the film 11 along 3 separates it from the surface of the film 11.

(C) Film shift movement control mechanism (see FIGS.
3, 5-7) Driving of endless film 11 and driven roller 13
As shown in FIG. 2, the bearing 12 is disposed between the front side plate 19 and the rear side plate 18 of the fixing device 1 as a bearing. 21.
Reference numeral 20 denotes a bearing on the front end side and a bearing on the rear end side of the driven roller 12.

Here, the driving roller 13 and the driven roller 1
2, parallelism of heater 14, and pressure roller 15 (X
Unless the accuracy in the axial direction, the Y-axis direction, and the Z-axis direction) is set to ± 0, when the drive roller 13 is driven to rotate the film 11 in the direction of arrow a, the film 11 suspends it. 1 and 2 depending on the positional relationship (variation in each direction of the X, Y, and Z axes) of the three members, that is, the rollers 13 and 12 and the heater 14 that are wound around as the film transport path member.
Of the film 11 indicated by the solid line, a shift occurs along the length of the rollers 13 and 12 toward the right side C (front end side) or the left side B (back end side) in the film width direction. The end of the film rubs against the side plate 19 or the side plate 18 and is damaged.

Therefore, in this embodiment, the bearing 20 on the rear end side of the driven roller 12 is indicated by arrows P and Q with respect to the side plate 18.
An oscillating lever (fork lever) 6 is provided rotatably for supporting the movable bearing 12 in the up-and-down direction and engaging with the rear bearing 20 to displace the roller 12. Is driven by the stepping motor 23. When the stepping motor 23 rotates in the clockwise direction, the rear end side of the driven roller 12 rotates upward in the arrow P and in the counterclockwise direction, and is displaced in the downward direction in the arrow Q. At this time, depending on the displacement direction of the driven roller 12, the turning endless film 11 changes its deviation direction to the back side of the arrow B in the case of the arrow P and to the front side of the arrow C in the case of the arrow Q.

At this time, by controlling the number of drive pulses applied to the stepping motor 23, the tilt amount of the driven roller 12 can be changed and the shift speed of the endless film 11 can be varied.

Reference numeral 16 is a photo sensor for detecting the shift position of the film. Further, as shown in FIGS. 2 and 5, the end portion 3 on the front side of the film 11 is masked as shown by hatching so as to shield the light from the photosensor 16 around the entire edge.

In this embodiment, the photo sensor 16
Although a photo interrupter is used as the above, when a reflection type photo sensor is used, the end portion 3 of the film 11 needs to be treated with a reflecting member that reflects light. Further, it may be read by a photo sensor via a movable piece that moves along the edge of the film 11.

In this embodiment, the masking or the like is applied to only one end of the film 11. However, it goes without saying that it may be applied to the entire film.

Reference numeral 4 denotes a cleaning member at the end of the film. The end of the film is always cleaned so as to prevent erroneous reading when a reflective sensor is used due to dirt on the end of the film. There is something. Although felt is used in this embodiment, any kind of felt may be used as long as it has a cleaning effect.

FIG. 5 shows the outer shape of the film 11. This film is an endless belt as described above, and its diameter is φM. Also, as shown in the figure, film 1
One end (end on the front side) of 1 is cut diagonally,
Let Lmax be the length of the longest part and Lm be the length of the shortest part.
If it is in, the dimension of the diagonally cut portion (diagonal cut portion) of the film 11 is obtained by Lmax-Lmin, and here it is designated as ΔL (diagonal film cut amount). As shown in FIGS. 1 and 2, the oblique cut portion is arranged on the front side of the fixing device, and the photosensor 16 detects the position of the film 11.

FIG. 6 shows the photo sensor 16 and the film 11.
3 is a detailed view of the positional relationship of FIG. In this embodiment, the photo sensor 16 is a transmissive photo interrupter.
The detection position is indicated by b. This is the photo sensor 16 when the film 11 is on the back side of the position of b.
Will be turned on, and will be turned off when it is on the front side of the position of b. Further, the diagonal cut portion of the film 11 is configured to be at the detection position b.

That is, the photo sensor 16 is turned on / off by the film 11 rotating in the direction of arrow a.
As a result, the ON / OFF cycle ratio (duty ratio) varies depending on the film position (closer position).

The film position shown in FIG. 6 represents a reference position where the center of the oblique cut portion of the film 11 is located at the detection position b of the photo sensor 16.

The graph of FIG. 7 shows the relationship between the film position and the OFF time of the photo sensor 16 with the reference position of the film as the center. That is, the OFF time of the photo sensor 16 is c seconds when the film 11 is at the reference position b, and the OF sensor of the photo sensor 16 is OFF when the film 11 is at least ΔL / 2 and before the reference position b.
F time is 0 seconds.

On the contrary, when the film 11 is at least ΔL / 2 behind the reference position b, the photo sensor 16
Will continue to be turned off.

O when the position near the film 11 is immediately before the position where the photo sensor 16 is kept off.
The FF time is d seconds, which can be considered to be almost equal to the time it takes for the film 11 to make one round, and the OFF time c second at the reference position b is the center of the film diagonal cut portion. The time is almost half of d seconds.

(D) Film shift movement control circuit (FIG. 8) FIG. 8 is a schematic diagram of a control system.

Reference numeral 26 is a microcomputer, and the photosensor 16 is connected to its input terminal IN1. A stepping motor 23 is connected to the output terminal OUT1. A rotation control signal for the motor 27 is output to the output terminal OUT2.

A + 5V power source is connected to the Vcc terminal,
The GND terminal is connected to the ground.

Although not shown, the copying machine using the fixing device 1 is provided with other input signal and output signal terminals. In addition to a ROM and a RAM in which a sequence program and the like are programmed, a nonvolatile RAM that retains the stored contents even if the power supply to the microcomputer 26 is cut off is built in.

(E) Control Program (FIGS. 9-12) FIGS. 9-12 show the flow chart of the film shift control program of the fixing device 1.

This program is also programmed in the built-in ROM in the above-mentioned microcomputer 26, and is called and executed by the main sequence program or the like at fixed time intervals or when necessary. It is like this.

First, after the start, in step 1 (FIG. 9), it is determined whether or not the motor 27 is on. If the main motor 27 is turned on, the process proceeds to step 2, and if the motor 27 is turned off, the process returns to step 1 and waits until the motor 27 is turned on.

In step 2, the stepping motor 23 for the forward deviation control is initialized. In this initialization operation, the stepping motor 23 is rotated counterclockwise and is rotated until the driven roller 12 abuts on a lower stopper member (not shown). After that, this abutting position is set as 0 point, and the position of the axis is controlled by the number of pulses from this point. Then go to step 3.

In step 3, the stepping motor 23 is rotated by the number of steps of the driven roller position stored in a predetermined address on the nonvolatile RAM in the microcomputer 26. In this embodiment, the driven roller 1
To set 2 to the midpoint position, set the position to 50 steps.

In step 4, it is judged whether or not the sensor 16 is OFF. If the sensor 16 is ON, the process proceeds to step 8, and if it is OFF, the process proceeds to step 5.

At step 5, the value of the error timer is set to 0.
Then, the measurement is started and the process proceeds to step 6.

At step 6, it is judged whether or not the sensor 16 is ON. If not, the process proceeds to step 7.

In step 7, the error check routine is executed and the process returns to step 6.

The content of the error check routine will be described with reference to FIG. 11. First, in step S1, it is determined whether or not the motor 27 is ON. If it is ON, the process proceeds to step S2. 1
3 (FIG. 10).

In step S2, the error timer value is d.
It is determined whether or not it is larger than the second. If it is smaller than the second, the process proceeds to the exit of this routine. Step S2
When the error timer value is larger than d seconds in step S3, the process proceeds to step S3.

In step S3, an error flag is set and the routine exits.

Next, when the sensor 16 is ON in step 6, the process proceeds to step 8, the value of the error timer is reset to 0, the measurement is started, and the process proceeds to step 9.

In step 9, it is judged whether or not the sensor 16 is OFF. If it is not OFF, the process proceeds to step 10, the error check routine is executed, the process returns to step 9, and if the sensor 16 is OFF, The process proceeds to step 11, resets the value of timer 1 to 0, starts measurement, and proceeds to step 12 (FIG. 10).

In step 12, it is judged whether or not the motor 27 is ON. If it is ON, step 1
Go to 4.

In step 14, it is judged whether or not the sensor 16 is ON. If it is not ON, the process proceeds to step 15 to execute an error check routine, and the process returns to step 14. If it is ON, the process proceeds to step 16. To do.

In step 16, the position of the driven roller 12 is changed according to the measured value of the timer 1. The measured value of the timer 1 is a value from 0 to d, which is divided into 5 stages,
The position of the driven roller 12 is controlled. It is shown in Table 1. As shown in Table 1, 90 steps when 0 to d / 5, 70 steps when d / 5 to 2d / 5, 2d / 5
Since it is in the vicinity of the center when ˜3d / 5, it is set as 50 steps, and similarly, when 3d / 5 to 4d / 5 is set to 30 steps, and when 4d / 5 to d is set to 10 steps. Then, the current position of the driven roller 12 is stored in a predetermined address on the RAM in the microcomputer 26. Then, the process proceeds to step 17.

[0076]

[Table 1] In step 17, the value of the error timer is reset to 0, measurement is started, and the process proceeds to step 18.

At step 18, the sensor 16 is turned off.
If it is not OFF, the process proceeds to step 19, the error check routine is executed, and the process returns to step 18.

If the sensor 16 is off in step 18, the process proceeds to step 20, where the value of the timer 1 is reset to 0, the measurement is started, and the process returns to step 12.

In step 12, the motor 27
If is OFF, the process proceeds to step 13, first stops the measurement of the timer 1 and resets the measured value to 0,
Next, turn off all phase excitation of the stepping motor 23.
Then, the process returns to step 1.

Although not described in detail, the stepping motor 23 is driven at the current position in the RAM. For example, when the current position is 30 steps and 70 steps, move 50 steps clockwise. When the current position is 30 steps and 10 steps, move counterclockwise 20 steps.

FIG. 12 shows a flow chart of a film abnormality processing program which is a part of the main program. Here, it is determined in step 24 whether or not the error flag is set, and if it is not set, the process goes to the exit and the next main sequence program is executed.

If the error flag is set in step 24, the process proceeds to step 25, all the outputs of all the devices (copiers in this embodiment) are turned off, and then the process proceeds to step 26. Abnormality is displayed and step 26 is set as a permanent loop so that the main program cannot be executed.

As described above, the main motor 27
The endless film 11 of this fixing device
First, the stepping motor 23 is controlled according to the contents of the non-volatile RAM that stores the driven roller 12 that has been controlled until then.

Next, when the main motor is rotating, the sensor 16
When is on, wait until it is turned off, and sensor 1
When 6 is OFF, it waits until it becomes ON, and then waits until it becomes OFF, and the timing at which the output of the film position sensor 16 switches from ON to OFF is detected, and the initial setting ends.

Then, the sensor 16 turns from OFF to ON.
The position of the film 11 is detected only after measuring the OFF time of the sensor 16 before switching to.

The displacement amount of the driven roller 12 is increased as the position of the film is farther from the center. When the film is near the center, the driven roller 12 is moved to the center. After that, sensor 1
The position of the film is judged by measuring the OFF time of the sensor 16 from the timing when 6 is switched from ON to OFF until it is switched from OFF to ON, and the position of the driven roller 12 is controlled accordingly.

In this embodiment, a transmissive photosensor is used as the sensor 16, but it goes without saying that the same applies if a sensor such as a microswitch or a reflective photosensor is used.

In this embodiment, the stepping motor 23 is used to change the amount of displacement of the driven roller 12 for the purpose of deviation control. However, the same effect can be obtained by using an eccentric cam and a clutch.

Further, in this embodiment, the previous driven roller position is stored in the non-volatile memory, but the non-volatile memory is not used, and when the power is turned on, control is performed with a predetermined initial value to shift the film shift position. After the detection, it may be changed according to the control. Further, the switching to the film position is not limited to only five steps, but may be any number of steps.

<Second Embodiment> This embodiment does not control the displacement of the driven roller 12 by dividing the film shift position into five stages as in the first embodiment, but continuously controls the displacement. It is a thing.

The position of the film is judged by the timer value of 0 to d. With respect to this timer value, the step position of the stepping motor 23 is controlled to − (80 steps × timer value) / d + 90 steps. In this case, 50 when timer value is 1 / 2d
Steps, 90 steps when d, 10 steps when 0. This enables finer position control.

<Third Embodiment> (FIG. 13) In this embodiment, the end portions of the endless film 11 are detected by a plurality of sensors 103 to 108 as shown in FIG.

Both ends 3 and 3 ′ on the front side and the back side in the width direction of the film 11 are masked so as to shield the light of the photosensor along the circumference of the film.

The sensors 103 to 108 are photosensors, and three sensors 104, 106, 108, 103, 105 are provided respectively on the front side and the back side of the film 11 in the width direction.
Numeral 107, which are arranged in the film circumferential direction, detect the film position respectively.

The sensors 105 and 106 are the sensor 103.
The sensor 107 is installed so as to detect the outer film position by the film detection position of 104.
108 is installed so as to detect the film position outside the sensors 105 and 106. 101 and 102 are cleaning members for the film edges 3 and 3 '.

In this embodiment, the photo interrupter is used as the photo sensor. However, when the opposite type photo sensor is used, opposite end portions 3 and 3'of the film 11 are treated with opposite members which oppose light. is necessary. It may also be detected via a movable piece that moves along the edge of the film.

The other hardware structure is the same as that of the first embodiment.

The number of steps of the stepping motor 23 is changed and the amount of displacement of the driven roller 12 is changed according to the detection signals of the photo sensors 103 to 108. The relationship is Table 2
Photo sensor 103 is ON, and 105 and 107 are O
When FF ... 40 steps Photo sensor 103/105 is ON, 107 is O
When FF is ... 30 steps When photo sensor 103, 105 and 107 are ON, 20 steps are taken. Also, the photo sensor 104 is ON, and 106 and 108 are O.
When FF ... 60 steps Photo sensor 104/106 is ON, 108 is O
70 steps when FF ... 80 steps when photosensors 104, 106 and 108 are ON.

Then, when all the photosensors 103 to 108 are OFF ... 50 steps (middle point).

[0100]

[Table 2] The number of photosensors is not limited to six in this embodiment, and any number of photosensors may be used as long as it is two or more. As described in the first to third examples above, the lateral movement position of the endless film 11 in the width direction is detected at a plurality of positions, and the closer the endless film 11 is to the position farther from the center, the greater the deviation force is. By making it stronger, it is a stable film that does not apply an undesired offset force to the film from the initial state, and does not cause extreme damage to the film even if the film shift speed changes due to durability or thermal changes. It is possible to control the deviation.

<Fourth Embodiment> (FIGS. 14 to 19) (A) Example of image forming apparatus (FIG. 14) FIG. 14 shows an image forming apparatus equipped with an image heating and fixing device 1 as a heating device according to the present invention. The schematic structure of an example is shown.

The image forming apparatus of this example is a transfer type electrophotographic copying apparatus in which a manuscript table is fixed and one optical system is moved, a rotary drum type photosensitive member is used, and double-sided / multiple copying is possible. The image forming principle, process, and mechanism configuration of the apparatus of this example are publicly known, so that the description will be briefly described.

Reference numeral 170 denotes a fixed original platen glass, and an original 0 is placed on the upper surface of the original platen glass according to a predetermined placing standard with the image surface to be copied facing downward, and on the original platen cover 171.
Set by covering.

The rotating drum type photoconductor 172 is rotationally driven in the clockwise direction indicated by the arrow at a predetermined peripheral speed (process speed) by the copy start signal, and the peripheral surface of the photoconductor is uniformly charged to a predetermined potential by the charger 173. It

Further, the moving illumination lamp 174 of the image forming optical system is used.
The moving first mirror 175 is set at a predetermined speed V, and the moving second mirror 176 and the third mirror 177 are set at a speed V / 2 by being reciprocally driven from the left side to the right side of the platen glass 170. The downward image surface of the document 0 is sequentially optically scanned from the left side to the right side, and the scanned document image is formed by the imaging lens 178, the fixed fourth mirror 179, and the fifth mirror 180.
By the image formation exposure L on the surface of the rotating photoconductor 172 charged by the charger 173 through the sixth mirror 181, an electrostatic latent image corresponding to the original image is formed on the peripheral surface of the photoconductor 172. It is formed in sequence.

The latent image is subsequently visualized by the developing device 182 with toner (developer) made of resin or the like that softens and melts by heating.

Then, the visualized toner image is transferred from the first paper feeding cassette unit 183 or the second paper feeding cassette unit 184.
Alternatively, by using the manual feeding means 185, 1
Sheets are fed one by one, and are sequentially transferred onto the surface of a transfer material sheet as a recording material that is fed to the transfer portion between the photoconductor 172 and the transfer / separation charger 187 at a predetermined timing by the registration roller pair 186. To go.

The transfer material sheet that has received the image transfer is the conveying device 1.
When it is introduced into the fixing device 1 at 88, it undergoes an image fixing process and is discharged outside the machine as an image formed product (copy) by the paper discharge roller 189 (in the case of the single-sided copy mode).

In the case of the double-sided or multi-copying mode, the transfer material sheet that has exited the fixing device 1 and has been copied on one side or has been copied for the first time is introduced into the re-conveying sheet path mechanism section 190,
Double-sided or multiplex copying is executed by re-feeding the paper to the transfer unit 187 with the front and back reversed or without the front and back reversed.

After the image transfer, the photoconductor 172 is cleaned by the cleaning device 191 to be a clean surface, and is repeatedly used for image formation.

(B) Fixing Device 1 (FIGS. 15 and 16) FIG. 15 is a plan view of the image heating and fixing device 1 as the heating device used above, and FIG. 16 is a side view thereof.

The fixing device 1 of this embodiment also includes an endless film 11, a film driving roller 13, a driven roller 12,
It is composed of a heater 14 as a heating body and is basically the same as the device of the first embodiment (FIGS. 1 to 3). The same reference numerals are given to common constituent members and portions, and repetitive description will be omitted. The fixing operation / principle of the toner image on the transfer material sheet is the same as that of the first embodiment.

(C) Film shift movement control mechanism (see FIG. 15)
-19) In the present example, the back side of the driven roller 12 is also vertically displaced P / Q.
By doing so, the film 11 is moved to the back side B in the width direction.
Alternatively, the film 11 is controlled to move toward the front side C, and the film 11 is controlled to move infinitely back and forth within a predetermined deviation range.

Reference numeral 30 denotes a vertical displacement mechanism on the back side of the driven roller 12. 31 is a downward arm connected to the back side bearing 20 of the driven roller 12, 32 is a screw receiver (female screw member) fixed to the lower end of this arm, 33 is a vertically oriented screw (male screw rod) screwed into this screw receiver 32. Reference numeral 34 designates a bearing on the upper end of the screw, and 23 designates a stepping motor (step motor) arranged on the lower end side of the screw 33 with the rotating shaft facing upward. The rotating shaft of the motor and the lower end of the screw 33 are cup-shaped. They are connected via a ring 35.

The screw 33 is the stepping motor 2
It is driven to rotate in the forward rotation direction (CW direction) / reverse rotation direction (CCW direction) by the forward / reverse rotation drive control of 3, and the screw receiver 32 and the arm 31 move up and down in accordance with the rotation amount of the screw 33. As a result, the rear end of the driven roller 12 is vertically displaced P · Q.

Since the gear reduction ratio of the screw 33 and the screw receiver 32 is very high, the position of the screw 33 and the screw receiver 32 does not move under the force of the driven roller 12.

FIG. 17 is a development view of the endless film 11, and as shown in the drawing, the end portion on the back side of the film 11 has an oblique cut edge (mountain cut edge) 3a.

Reference numeral 36 is a lever (actuator) for detecting the lateral position of the film 11, and the vertical axis 37
With the biasing spring 39, the first arm portion 36a of the lever 36 is constantly biased in the counterclockwise direction by the biasing spring 39 so that the diagonal cut edge of the film 11 is constantly rotated. It is in contact with 3a. Reference numeral 38 is a transmissive sensor (photo interrupter), and the second arm portion 36b of the lever 36 corresponds to the detection portion of the sensor 38.

As described above, the back side edge portion 3 of the film 11
Since a is an oblique cut edge, the lever 36 is attached to the film 11
The movement is repeated periodically in the D and E directions according to the rotation of. Therefore, the second arm portion 36b of the lever 36 periodically interrupts the detection portion of the transmissive sensor 38,
As an output of the sensor 38, a square wave having a constant period is obtained.

Here, a transmissive sensor called a so-called photo interrupter is used as the sensor 38, and a high output is obtained when the detection section is blocked, and a low output is obtained when the detection section is not blocked. Since the number of rotations of the film 11 is constant and is 0.526 rotations / second,
The frequency obtained from the sensor 38 is about 1.05 Hz (in the case of the shape of the oblique cut edge 3a in FIG. 17, the film 1
One revolution of 1 produces an output waveform of 2 cycles). Here, when the film 11 starts to approach the back side direction B in the width direction, the timing of interrupting the sensor detection portion of the second arm portion 36b of the lever 36 changes, so the frequency of the output waveform of the sensor 38 does not change, The high period is long and the low period is short, and the duty of the square wave is large. When the film 11 starts to shift in the reverse direction C, the duty becomes smaller.

FIG. 18 shows shifts B and C of the film 11 and changes in sensor output. F is a cycle of one rotation of the film 11.

T1 is a timing chart of the sensor output waveform when the film 11 is at the reference position, and the duty is about 50%.

On the other hand, T2 is a timing chart of the output waveform when the film 11 is moved to the sensor 38 side from the reference position, that is, the back side B in the film width direction, and the duty is about 70%.

On the other hand, T3 is a timing chart of the output waveform of the sensor 38 when the film 11 moves to the side opposite to the sensor 38 side from the reference position, that is, the front side C in the film width direction, and the duty is about 30%. It has become.

As described above, the square wave of the sensor output has a constant cycle and the duty changes continuously depending on the position near the film 11. Therefore, the deviation position of the film 11 can be determined by measuring either the high period or the low period of the sensor output waveform.

Reference numeral 40 is a control board for controlling the apparatus, which is composed of a microcomputer and peripheral circuits. 41 is a motor drive circuit board, 27 is a main motor that drives the main load of the apparatus, and is connected to the drive roller 13 by a mechanical mechanism (not shown).

The entire sequence of the apparatus is controlled according to the program stored in the ROM inside the microcomputer mounted on the control board 40, and the copying operation is executed. When a start signal of the main motor 27 is output from the microcomputer in accordance with the copying operation, the motor drive board 41 drives the main motor 27.

When the main motor 27 rotates, the drive roller 13 connected by a timing belt and a gear train (not shown) rotates, the film 11 is rotationally driven a, and the driven roller 12 also starts to rotate.

With the rotation of the film 11, the lever 36 swings D / E by the diagonal cut edge 3a of the film, and the sensor 38 outputs a square wave. This square wave output is
The pulse width is input to the input port of the microcomputer and the pulse width is measured by the internal timer of the microcomputer. The microcomputer controls forward / reverse rotation of the stepping motor 23 based on the measured value to control the shift of the film 11.

(D) Control Program (FIG. 19) Next, the algorithm for the film shift movement control performed by the microcomputer will be described with reference to the flowchart of FIG. Here, what is shown as a flow chart is a subroutine that is periodically (10 ms cycle) called only during the rotation of the main motor 27 in the sequence program of the copying operation.

When this subroutine is called, the routine process is started from step 301.

At step 302, the pulse width of the square wave is PULSE. It is called from internal memory (RAM) labeled WIDTH. The pulse width measured by a so-called timer interrupt routine is stored in this memory while being constantly updated.

Next, at step 303, it is judged from the flag whether or not the measurement value is read for the first time, and if it is the first time, the routine proceeds to step 304, where the pulse width is set to PULSE. ME
The data is stored in the memory labeled MO, and this subroutine is exited from step 312 to return to the caller.

If it is not the first time in step 303, the process proceeds to step 305 and the pulse width is 475 ms.
Judge whether or not the above. Here, if it is 475 ms or more, the routine proceeds to step 306, where the pulse width is “PULSE MEM
O + 30 ms ”or more, and if not, proceed to step 312 to end the subroutine, and if not, proceed to step 308 and PLUSE Store the pulse width in MEMO and update the contents.

Further, the process proceeds to step 309, and a start flag for rotating the stepping motor 23 in the forward direction is set,
The subroutine is exited from step 312.

In step 305, the pulse width is 475 ms
If not, proceed to step 307, where the pulse width is "PULSE". MEMO-30 ms "or less, and if not, go to step 312 to end the subroutine. If not, go to step 310 and PU.
LSE Store the pulse width in MEMO and update the contents.

Further, the process proceeds to step 311, and a start flag for reversing the stepping motor 23 is set,
Exit the subroutine from 312.

In this subroutine, when the normal or reverse rotation start flag of the stepping motor 23 is set,
A routine for controlling the stepping motor controls the rotation of the motor 23 by outputting a drive pulse in forward or reverse rotation for 10 steps according to this flag, resets the start flag, and ends the process.

Repeating the schematic description of the above operation, this copying apparatus is controlled by a control board having a microcomputer mounted therein, like the ordinary copying apparatus, and the control program is masked in the internal ROM of the microcomputer.

This microcomputer has an internal ROM
It is a so-called one-chip microcomputer in which the internal RAM, timer control, interrupt control, serial control, 8-bit / 8-channel A / D converter, and I / O port units are integrated on-chip.

During a copying operation or the like, a drive signal for the main motor 27 is output from the output port of the microcomputer to the motor drive circuit board 41 to activate the main motor 27. The main motor 27 is connected with loads such as a photosensitive drum, a paper feeding system, a fixing system, and a conveying system via a timing belt, a gear train, and the like, and the driving roller 13 of the fixing device 1 rotates in conjunction with the load. start. As a result, the film 11, driven roller 12, and pressure roller 15 also start to rotate.

When the film 11 is rotated, the sensor lever 36 for detecting the film position is pushed and oscillated along the mountain-shaped cut edge 3a at the end of the film to turn on / off the transmissive sensor 38, and from the sensor, A square wave whose duty ratio indicates the position of the film is output. This square wave is input to the input port of the microcomputer, the high output period width (pulse width) is measured by the internal timer, and the value is stored in the internal RAM.

Since the period of the square wave is constant as long as the rotation speed of the film 11 does not change, the degree of deviation of the film 11 toward one side or the other side in the width direction of the film 11 can be determined.

The rotation cycle of the film 11 is about 0.525H.
Since it is mechanically configured in z, the sensor output is about 1.05 Hz because the sensor output is two cycles per film rotation (in the case of film 11 in FIG. 17), and the pulse width at a duty of 50% is about. It becomes 475 ms. Here, when the film 11 is at the center (reference position) with respect to the axial direction of the driving roller 13, the pulse width is about 475 m.
If the mounting positions of the sensor lever 36 and the sensor 38 are adjusted so as to be s, the film 11 is closer to the sensor 38 side (B) than the center in the width direction when the pulse width is 475 ms or more.
If it is 475 ms or less, it can be determined that the sensor 38 is closer to the side opposite to the sensor 38 side (direction C).

Further, the pulse width is measured at arbitrary time intervals,
It can be seen that if the width tends to increase, it is moving in the B direction, and if the width tends to decrease, it is moving to the opposite side.

Therefore, in the control algorithm of this embodiment,
The pulse width is measured every 10 ms, and the pulse width is 475 ms.
In the above case (the film 11 is closer to the sensor 38 than the center), the step motor 23 is extended every time the pulse width is extended by 30 ms.
Is rotated in the forward direction by 10 steps to displace the rear end portion of the driven roller 12 in the downward Q direction and gradually increase the biasing force for returning to the center (returning force in C direction). Then, the movement is controlled to be stopped or reversed.

On the other hand, when the pulse width is less than 475 ms (the film 11 is on the side opposite to the sensor 38 side from the center), the step motor 23 is turned on every time the pulse width is reduced by 30 ms.
By rotating the driven roller 12 in the reverse direction by 0 step, the rear end portion of the driven roller 12 is displaced in the upper P direction, and the biasing force for returning to the center stepwise (returning force for B direction) is increased. Control to stop or reverse the movement.

By controlling in this way, the film 11 is controlled so that the moving speed is gradually decreased to the stop, and the film 11 is slowly rotated repeatedly in the vicinity of the center to rotate.

As described above, in the present embodiment, the control value for the film shift movement is set in multiple steps, and the control is performed to minimize the film shift movement speed instead of the simple position control. Film 1 with sufficient support
It was possible to reduce the stress on No. 1 and improve the durability of the film 11.

Further, since the shift speed of the film is slowed down, the positional accuracy can be improved with easy control.

[0151]

As described above, according to the present invention, in the film heating type heating device using the endless film, the film deviation control is always stable regardless of the involvement of the unstable factors. Transport becomes possible, and the reliability of the device can be improved. Further, the film shift control means can be easily implemented without complicating the structure and increasing the size.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part of a first embodiment device.

FIG. 2 is a plan view of the device with an intermediate part omitted.

FIG. 3 is a side view of the device.

FIG. 4 is a schematic diagram of an example of an image forming apparatus.

[Fig. 5] Outline drawing of endless film

FIG. 6 is an explanatory view of the relationship between the film sensor and the film position.

FIG. 7 is a graph showing the relationship between film position and film sensor output.

FIG. 8 is a schematic diagram of a control system.

FIG. 9 is a flowchart of a film shift movement control program.

FIG. 10 is a flowchart of a film shift movement control program.

FIG. 11 is a flowchart of a film shift movement control program.

FIG. 12 is a flowchart of a film shift movement control program.

FIG. 13 is a plan view of the device according to the third embodiment, which is omitted in the middle thereof.

FIG. 14 is a schematic diagram of an example of an image forming apparatus including the apparatus of the fourth embodiment.

FIG. 15 is a plan view of the fixing device.

FIG. 16 is a side view of the device.

FIG. 17: Development view of film

FIG. 18: Change diagram of sensor output

FIG. 19 is a flowchart of a film shift movement control program.

[Explanation of symbols]

 11 Endless Film 12 Driven Roller 13 Drive Roller 14 Heating Body 15 Pressure Roller 16 Film Side Position Detection Sensor

Front page continuation (72) Inventor Kazuki Miyamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Teruo Mitsui 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Jun Chaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takahiro Takahiro, 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Akihiro Sakai 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (3)

[Claims] 1. An endless film, and a heating body disposed on the inner surface side of the endless film, and a heated body is brought into close contact with the outer surface side of the endless film to convey and pass the heating body position together with the film. It is a heating device of a film heating system that gives the heat of the heating body to the object to be heated through the film, and when the direction orthogonal to the transport direction of the endless film is the film width direction, in the transport process of the endless film. The film shift control unit has a film shift control unit that makes the shift motion of the film in the width direction infinitely reciprocating within a predetermined range. The film shift control unit detects a plurality of shift positions in the width direction of the endless film. It has one or more detecting means, and means for controlling the lateral movement speed of the endless film in the width direction according to the detection signal of the detecting means. Heating apparatus according to claim. 2. An endless film having means for displacing a transport path member of the endless film to switch the direction of the lateral movement of the endless film in the width direction, and changing the displacement amount of the transport path member of the endless film. The heating device according to claim 1, further comprising means for controlling a lateral movement speed of the sheet. 3. An endless film and a heating body disposed on the inner surface side of the endless film, and a heated body is brought into close contact with the outer surface side of the endless film to convey and pass the heating body position together with the film. It is a heating device of a film heating system that gives the heat of the heating body to the object to be heated through the film, and when the direction orthogonal to the transport direction of the endless film is the film width direction, in the transport process of the endless film. Position detection means to detect the film deviation position, film deviation force changing means that can change the lateral direction deviation force of the endless film in multiple steps, and the endless film separates from the predetermined reference position When it is detected by the position detecting means that the moving object is moving in the direction of An endless film deviation control means configured to decrease the moving speed of the endless film in the detaching direction by controlling the deviation force varying means so as to increase stepwise by an amount. Heating device.